Welcome to barricade, a simple implementation of the port knocking method
aimed to open your network service or firewall only if a special icmp echo
request packet is sniffed from the network interface. After the last valid
packet received, barricade waits for a defined amount of time, then it closes
your firewall or stops your services. There is a client included in the
package called barricade_client that helps you to create special icmp packets
containing the password.

To compile barricade you need gcc and libpcap headers (>= 0.6.2).
Simply run

make

to compile the program and

make install

to install. Installation paths are defined in ./scripts/install.sh. This
script is
suitable for debian users (and perhaps for many other distros) but you
may need to
edit some parameters. Don't forget to edit uninstall.sh to reflect changes
made on
install.sh if you plan to uninstall barricade.
./etc/barricade.conf is a sample configuration file, with comments. Edit
this file to
suit your needs and put it on /etc/.

Debian Installation

Download the tarball then run

make deb
dpkg -i barricade-0.0.1.deb

to install barricade on your debian distro. dpkg will select the package
libpcap0
automatically (debian rules ;)). The configuration file is /etc/barricade.conf.
After editing this file, run

barricade was developed only for fun in May 2004 by Francesco Vannini.
Feel free to
send me an email concerning barricade bugs, improvements, advices, comments
or whatever
you want to vannini@gmail.com